You create a portfolio that invests 60% in stock A with E(rA) = 15%, A = 10% and 40% in stock B with E(rB) = 10%, B = 4%.

1. Estimate the expected return of the portfolio.

2. Estimate the standard deviation of the portfolio if the two stocks are uncorrelated.

3. Estimate the standard deviation of the portfolio if the two stocks have correlation 0.5.

4. Estimate the standard deviation of the portfolio if the two stocks are perfectly positively correlated.